At first, he was a commander in Changshu. Later, he became the commander of Jin Wu, known as "Zhang Changshi".
Tang Wenzong once wrote a letter, regarding Li Bai's poems, Pei Min's sword dance and Zhang Xu's cursive script as "three unique skills". He also wrote poems, and was called "Four Gentlemen of Wuzhong" with He, Zhang and Bao Rong.
Zhang Xu's calligraphy began with Zhangzhi and Erwang, with cursive script as the highest achievement. Primitive weeds are called "sages of grass" in history.
Du Fu befriended Li Bai and He Hao, and was listed as the "Eight Immortals of Drinking".
Du Fu once wrote a poem: "Zhang Xu's three cups of grass are sacred. Take off your hat and show it to the top of the prince, waving paper like a cloud."
There are "Stomach Pain Sticks" and "Four-character Poems" handed down from ancient times.